1. Field of the Invention
The present invention relates to the field of displaying technology, and in particular to a method for manufacturing a flexible display device.
2. The Related Arts
Currently, in the field of displaying technology, a variety of displaying techniques is available for flexible display devices. Examples include the traditional liquid crystal display techniques, bistable liquid crystal display techniques, organic light-emitting diode (OLED) display techniques, electrophoretic display techniques, electrochromism (EC) display techniques, and electroluminescent (EL) display techniques. Among them, a flexible organic light-emitting diode (FOLED) display has more advantages over the other flexible displays, such as self-luminous, fast response speed, high brightness, wide view angle, and low cost. Further, the FOLED display is a display based on flexible organic material, allowing for winding and folding and serving as a component of a wearable computer, all these making it widely applicable to specific fields, such as portable devices having excellent displaying performance and military uses.
A conventional flexible display device is generally formed of a flexible substrate having a thickness less than 100 micrometers, such as a piece of ultrathin glass, a stainless steel film, and a plastic substrate. Due to the problems of being readily fragile, wrinkling, and deforming, in the manufacturing of flexible substrates, two types of manufacturing process have been commonly adopted. The first one is illustrated in FIG. 1, where a flexible substrate 100 is laminated on a glass substrate 200 or is alternatively coated on a stiff substrate through a coating process, followed by processes of making thin-film transistor (TFT) arrays, making OLEDs, and packaging. Finally, the glass substrate or the stiff substrate is removed. Such a process may readily induce stress in during the manufacturing and the flexible substrate may readily warp and deform and requires the stiff substrate to function as a backing. The baking needs to be peeled and removed after the manufacturing and this may readily induce electrostatic damage. The second way is illustrated in FIG. 2, where a flexible substrate 100′ is wound around a roller 200′ through a winding process and then a manufacturing process is conducted thereon. Such a process has poor accuracy and is hard to control the pulling force and is generally not a mature technique.
Thus, one of the key issues of manufacturing a flexible display device is to effectively fix a flexible substrate.